Sensitized photographic emulsion



PatenteJMar S, 194s" I UNITED srarss PATENT pence ass-sue SENSITIZED PHOTOGRAPHIC EMULSION Burt a. ,carroll and John Spence, 'ltocliester, N. Y., assignors to Eastman Kodak Company, Rochester, N. 'Y., a corporation of New Jersey at Drawing. Application June 13,1944, j J V Serial No. musev r ,20 Claims. (cuss-1)? This invention relates to sensitized 'photo- Exemplary of the be'nzothiazolones are the 2(1)- graphic emulsions and more particularly to specbenzothiazolones, such as the compound of the trally (optically) sensitized emulsions.

It is known that the distribution ofspectral v sensitivity of certain spectrally sensitized emul- I sions can be altered and an increase of sensitivity obtained in some spectral region, by incorporating certain additional sensitizing dyes in the. spectraliy sensitized emulsions. (See United States Patents 2,158,882, dated May 16, 1939, and l '1 a 2,159,565, dated May 23, 1939.) The effect thus Exem ar o the thlwlinones are the i -t obtained has come'to be known as supersensitil no such as -n pv zation. Supersensitization of certain spectrally e. sthe co pound of the t o s ulas sensitized emulsions can also be eflected by incor- 'following formula:

s poratlng certain substantially colorless heterois H i f cyclic bases, viz., those containing an amino 1 '4 roup, in the spectrally sensitized emulsions. N/

a (See United States Patent 2,177,635, dated October 31, 1939.) Supersensitlzation differs from h persensitization which involves treatment of gg g e ggeg e q e finished films or plates, an operation which norg B I mally reduces the pAg and increases the pH of J theemulsions, with consequent decreased sta- H10 NEW. 0 a

We have now found a new method for super- 1 l I sensitizing spectrally sensitized emulsions, which I a not only does not reduce the stability of the emul- We are aware that certain heterocyclic nitrosions, but is especially valuable as a means of givgen bases containing a carbonyl group in the ing panchromatic sensitized emulsions of high heterocyclic ring havebeen employed in photo- Vspeed'and exceptionally good color balance. graphic emulsions heretofore as color couplers.

It is, accordingly, an object of our invention to Typical of such heterocyclic nitrogen bases are provide new supersensitized photographic emulhomophthalimide which can be represented by sions. A further object is to provide a process the following formula: for preparing such emulsions. Still other objects will become apparent hereinaften- E In accordance with the invention, a photographic silver halide emulsion spectrally sensi- NH tized with one or more cyanine dyes is supersensitized by incorporating in the emulsion a 1 g heterocyclic nitrogen base selected from the 40 1 81mm consisting benmtmazolones and 3-hydroxy pyridine which can be represented and thiazolimmes- Exemplary of the qmno by either of the following formulas: lones are: 2(1) -quinolone (carbostyril), the 4- 7 alkyl-2(1) -quinolone s, such as lepidone of the on formula: or

CH: 1 1 i N LO The, isoquinoline derivative (homophthalimide).-

however, is devoid of supersensitizing action. Three-hydroxy pyridine is likewise devoid'of suand the 1 quinolones, such persensitizing action; None of r the pyridones 1.3 umolone o t formula: show any marked supersensitizing action. Ac-' y f 5e cordingly, isoquinolones and pyridones are specifi- "'cally excluded from the purview of our invention.

' The majority of cyanine dyes which are super- 0 I sensitized by the heterocyclic nitrogen basesuu'e N g characterized by the fact that the dyes produce (mi two types of sensitization depending upon con-- ditions. Such different types of sensitization are described by Leermakers, Carroll and Stand, J. Chem. Physics, 5, 878 (1937) and by G. Schwarz, Sci. et Ind. Phot. 10, 233 (1939). When a cyanine dye of this type is used as a sensitizer in low concentration, it exhibits a sensitizing maximum displaced out 20 to 55 mu. toward the red from the absorption maximum in ethyl alcohol solution. On increasing the concentration of the dye, or upon digesting the: emulsion containing gdye in the lower concentration, or both, a secjofiid maximum of" sensitization develops at longer wavelengths, which may be accompanied by an increase in total optical sensitization. In some cases, a decrease in sensitivity at the first maximum can be detected. These phenomena are consistent with the hypothesis of two states of the sensitizing dye in an equilibrium which is controlled by concentration. The heterocyclic nitrogen bases favor the formation of a second maximum which occasionally is appreciably displaced from the normal second maximum. The

increase in sensitivity apparently corresponds to increased conversion of the dye to the state corresponding to the second maximum of sensitization. In some cases, the effect appears to correspond to a more complete conversion than has ever been obtained without asupersensitizer, and

in any case the long wavelength sensitivity is better than can be obtained from the same concentration of dye without the heterocyclic nitrogen base.

The following are exemplary of the cyanine dyes which can be supersensitized in accordance with our invention:

5,5 dichloro-3,3',9 triethylselenacarbocyanine bromide The sensitizing dyes can be employed in the same concentrations as would be used in the absence of the supersensitizer. Ordinarily from 10 to 30 mg. of dye per liter of emulsion will sumce to produce the optimum sensitizing eifect. The methods of incorporating sensitizing dyes in emulsions are well known to those skilled in the art. Ordinarily it is preferable to dissolve the dye in a water-miscible solvent, such as methanol or ethanol before incorporating in the emul sion. One or more sensitizing dyes can be employed.

The amount of heterocyclic nitrogen base employed is not critical. Usually the full supersensuch as methanol, before incorporation in the emulsion. The sensitizing dye or dyes and the heterocyclic nitrogen bases can be added to the emulsion at any convenient stage of its preparation, but preferably to the washed, finished emul-- sion.

The following examples will serve to illustrate results obtained in accordance with our invention.

Example 1 A fast negative gelatino-silver-bromiodide developing-out emulsion was sensitized with 3,3'-diethyl-Q-methylthiacarbocyanine bromide (20 mg. per liter of emulsion) and to a portion of the spectrally sensitized emulsion was added 2(1)- quinolone (carbostyril). A portion of the spectrally sensitized emulsion containing the quinclone and a portion of the spectrally sensitized emulsion without the quinolone were separately exposed, through red (Wratten 25) and minus blue (Wratten 12) filters, the latter giving a good measure of total optical sensitivity. The following results were obtained.

Red Minus blue 2(l)-quinolone (g. per F liter of emulsion) Speed Gamma Speed Gamma None 1. 41 435 l. 52 0. ll 5 255 1. 27 795 1. 30 10 Example 2 results were obtained.

4-methyl-2(l)-quino Red Minus lone (g. per liter 0! Fog emulslon) Speed Gamma Speed Gamma None 105 1. 61 535 1. 57 0. 09 1.25 225 1. 56 590 1. 58 11 Example 3 A fast negative gelatino-silver-bromiodide developing-out emulsion was sensitized with 5,5- dichloro-S,3',9-triethylselenacarbocyanine bromide (20 mg. per liter of emulsion), and to a portion of the spectrally sensitized emulsion was added 4-methyl-2(l)-quinolone. A portion of the spectrally sensitized emulsion containing the quinoline and a portion of the spectrally sensitized emulsion without the quinolon were separately exposed through red (Wratten 25) and minus blue (Wratten 12) filters. The following results were obtained:

4-rnethyl-2,(l)-quino- Red Minus blue lone (g. per liter of Fog emulsion) Speed Gamma Speed Gamma None 93. 5 l. 25 1. 24 0. 10 1.25 21 1. 28 310 1. 22 10 accuses I Our lnvention is primarily directed to the Example 4 A test negative gelatino-silver-bromiodide deiveloping-out emulsion was sensitized with 3,3- dlethyl-9-lnethylthiacarbocyanine bromide (20 mg. per liter of emulsion), and to a portion of the spectrally sensitized emulsion was added 1-methyl-2( 1) -quinolone. A portion of the spectrally sensitized emulsion containing the quinolone and a portion of the spectrally sensitized emulsion without the quinolone were separately exposed through red (Wratten '25) and minus blue (Wratten 12)fllters. were obtained:

A fast negative gelatino-silver-bromiodide developing-out emulsion was sensitized with 3,3'-

diethyl-Q-methylthiacarbocyanine bromide (20 mg. per liter'of emulsion), and to a portion of the spectrally sensitized emulsion was added The following results i customarily employed gelatino-silver-halide developing-out emulsions, especially gelatino-silverchlorobromide, gelatino-sllver-bromide and gesupport, glass support or paper support;

The quinolones, benzothiazolones and thiazolinones referred to herein are named and numbered in accordance with current recommenda,

tions of Chemical Abstracts. .What we claim as our invention and desire to be secured by Letters Patent of the United States is:

2(1) -benzothiazolone. A portion of the spectrally 1 sensitized emulsion containing the benzothiazolone and aportion of the spectrally sensitized emulsion without the benzothiazolone were separately exposed through red (Wratten and minus blue (Wratten 12). filters. The following results were obtained:

2(1)-benzothiazolone Minus blue (g. per liter of emul- FOE Speed Gamma Speed Gamma None 115 1.41 435 1.52 0.11 0.05 170 1.58 605 1,03 .12

Example 6 .A fast negative gelatino-silver-bromiodide developing-out emulsion was sensitized with 3,3'-

dlethy1-9-methylthiacarbocyanine bromide (20 mg. per liter of emulsion), and to a portion of the spectrally sensitized emulsion was added 2-|phenylam.ino-4-thiazolinone. A portion of the spectrally sensitized emulsion containing the thiazolinone and a portion of the spectrally sensitized emulsion without the thiazolinone were separately exposed through red (Wratten 25) and minus blue (Wratten 12) filters. The

following results were obtained:

2-phenylamino-4-thia- Red Minus Bluezolinone (g. per liter Fog emulsion) Speed Gamma Speed Gamma None 7a 1.43 490 1.46 6.10

Some" of the quinolones, e. g.'

1. A photographic silver halide emulsion-spec veloping-out emulsion spectrally sensitized with a cyanine dye, the emulsion containing, as a supersensitizer, a heterocyclic nitrogen base selected from a group consisting of 2(1)-quinolones, benzothiazolones and thiazolinones.

4. A photographic gelatino-silver-bromiodide developing-out emulsion spectrally sensitized with a cyanine dye, the emulsion containing, as a supersensitizer, a heterocyclic nitrogen base selected from the group consisting of 2(1)-quinolones, benzothiazolonesand thlazolinones.

5. A photographic gelatino-silver-halide developing-out emulsion spectrally sensitized with a cyanine dye, the emulsion containing, asa supersensitizer, a 2(1) -quinolone.

6. A photographic gelatino-silver-halide developing-out emulsion spectrally sensitized with a cyanine dye which produces a-maximum of spectral sensitivity in the emulsion at one concentration and at a higher concentration or upon digestion of the emulsion containing the dye at a lower concentration, produces a second maximum of spectralvsensitivity at a wavelength longer than that of the first maximum, said emulsion containing, as a supersensitizer, a 2(1) of spectral sensitivity in the emulsion at one concentration and at a higher concentration or upon digestion of the emulsion containing the dye at a lower concentration, produces a second maximum of spectral sensitivity at a wavelength longer than that of the first maximum,

said emulsion containing, as a supersensitizer, a 2( 1) -quinolone.

8. A photographic gelatino-silver bromiodide developing-out emulsion spectrally sensitized with a cyanine'dye which produces a-maximum of spectral. sensitivity in the emulsion at one concentration and at a higher concentration or upon digestion of the emulsion containing the dye at a lower concentration, produces a second maximum of spectral sensitivity at a wavelength longer than that of the first maximum, said emulsion containing, as a supersensitizer, a quinolone of the following formula:

9. A photographic glatino-silver-halide developing-out emulsion spectrally sensitized with a cyanine dye, the emulsion containing, as a supersensitizer, a 2(1) -benzothiazolone.

10. A photographic gelatino-silver-bromiodide developing-out emulsion spectrally sensitized with a cyanine dye, the emulsion containing, as a supersensitizer, a 2(l)-benzothiazolone.

11. A photographic gelatino-silver-halide developing-out emulsion spectrally sensitized with a cyanine dye which produces a maximum of spectral sensitivity in the emulsion at one concentration and at a higher concentration, or upon digestion of the emulsion containing the dye at the lower concentration, produces a second maximum of spectral sensitivity at a wavelength longer than that of the first maximum, the emulsion containing, as a supersensitizer, a 2(1) -benzothiazolone.

12. A photographic gelatino-silver-bromiodide developing-out emulsion spectrally sensitized with a cyanine dye which produces a maximum of .spectral sensitivity in the emulsion at one concentration and at a higher concentration, or upon digestion of the emulsion containing the dye at the lower concentration, produces a second maximum of spectral sensitivity at a wavelength longer than that of the first maximum, the emulsion containing, as a supersensitizer, a 2(1) -benzothiazolone.

13. A photographic gelatino-silver-bromiodide developing-out emulsion spectrally sensitized with a cyanine dye which produces a maximum of spectral sensitivity in the emulsion at one concentration and at a higher concentration, or

14. A photographic gelatino-silver-halide developing-out emulsion spectraliy sensitized with a cyanine dye, the emulsion containing, as a supersensitizer, a 4-thiazolinone.

15. A photographic gelatino-silver-bromiodide developing-out emulsion sp'ectrally sensitized with a cyanine dye, the emulsion containing, as a. supersensitizer, a i-thiazolinone.

16. A photographic gelatino-silver-halide developing-out emulsion spectrally sensitized with a cyanine dye, the emulsion containing, as a supersensitizer, a 2-phenylammo-4-thiazollnone.

1'7. A photographic gelatino-silver-bromiodide developing-out emulsion spectrally sensitized with a cyanine dye, the emulsion containing, as a supersensitizer a 2-phenylamlno-4-thiazolinone.

18. A photographic gelatino-silver-halide developing-out emulsion spectrally sensitized with a cyanine dye which produces avmaximum of spectral sensitivity in the emulsion at one concentration and at a higher concentration, or upon digestion of the emulsion containing the dye at the lower concentration, produces a second maximum of spectral sensitivity at a wavelength longerthan that of the first maximum, the emulsion containing, as a supersensitizer, a 2-phenylamino-i-thiazolinone.

19. A photographic gelatino-silver-bromiodide developing-out emulsion spectrally sensitized with a cyanine dye which produces a maximum of spectral sensitivity in the emulsion at one concentration. and at a higher concentration, or upon digestion of the emulsion containing the dye at the lower concentration, produces a second maximum ofspectrai sensitivity at a wavelength longer than that of the 'first maximum, the emulsion containing, as a supersensitizer, a 2-phenylamino-i-thiazolinone.

20. A photographic gelatino-silver-bromiodide developing-out emulsion spectrally sensitized with a cyanine dye which produces a maximum of spectral sensitivity in the emulsion at one concentration and at'a higher concentration, or upon digestion of the emulsion containing the dye at the lower concentration, produces a second maximum of spectral sensitivity at a wavelength longer than that of the first maximum, the emulsion containing, as a supersensitizer, the compound having the following formula:

BURT H. CARROLL. JOHN SPENCE.

Certificate of Correction Patent No. 2,395,846. March 5, 1946. URT H. CARROLL ET AL.

It is hereby certified that error appears in the ri ted specification of the above numbered patent requiring correction as follows: age 2, seeond column, line 41, Example 2, for quinoline reed quinolone an'd'thet the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiicev Signed and sealed this 21st day of May, A. 1946. e

LESLIE FRAZER,

First Assistant Commissioner of Patents. 

